Einasto Profiles and the Dark Matter Power Spectrum

Abstract

We study the mass accretion histories (MAHs) and density profiles of dark matter halos using N-body simulations of self-similar gravitational clustering from scale-free power spectra, $P(k)\propto k^n$. We pay particular attention to the density profile curvature, which we characterize using the shape parameter, $\alpha$, of an Einasto profile. In agreement with previous findings our results suggest that, despite vast differences in their MAHs, the density profiles of virialized halos are remarkably alike. Nonetheless, clear departures from self-similarity are evident: for a given spectral index, $\alpha$ increases slightly but systematically with "peak height", $\nu \equiv {\delta }_{sc}/\sigma (M,z)$, regardless of mass or redshift. More importantly, however, the "$\alpha -\nu$" relation depends on $n$: the steeper the initial power spectrum, the more gradual the curvature of both the mean MAHs and mean density profiles. These results are consistent with previous findings connecting the shapes of halo mass profiles and MAHs and imply that dark matter halos are not structurally self-similar but, through the merger history, retain a memory of the linear density field from which they form.

arXiv commentMNRAS letters, accepted

References in corpus (15)

• A Universal Density Profile from Hierarchical Clustering
• The cosmological simulation code GADGET-2
• Simulating the joint evolution of quasars, galaxies and their large-scale distribution
• Populating a cluster of galaxies - I. Results at z=0
• Cold dark matter haloes in the Planck era: evolution of structural parameters for Einasto and NFW profiles
• Concentration, Spin and Shape of Dark Matter Haloes as a Function of the Cosmological Model: WMAP1, WMAP3 and WMAP5 results
• The redshift dependence of the structure of massive LCDM halos
• A universal model for halo concentrations
• The Mass-Concentration-Redshift Relation of Cold and Warm Dark Matter Halos
• The Mass Profile and Accretion History of Cold Dark Matter Halos
• N-body Dark Matter Haloes with simple Hierarchical Histories
• A new way of setting the phases for cosmological multi-scale Gaussian initial conditions
• Dark Matter Halo Profiles in Scale-Free Cosmologies
• Gaussian Random Field: Physical Origin of Sersic Profiles
• Gaussian random field power spectrum and the Sérsic law

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